Removable power supply for an audio device

ABSTRACT

A method and apparatus are described for providing power to an audio signal processor. The method includes the steps of providing a receptacle for a housing of a voltage converting power supply within an enclosure of the audio signal processor and removably disposing the voltage converting power supply within the enclosure of the audio signal processor.

FIELD OF THE INVENTION

[0001] The field of the invention relates to audio devices. Moreparticularly, the invention relates to power supplies for audio devices.

BACKGROUND OF THE INVENTION

[0002] Power supplies for audio devices such as portable microphones andamplifiers are generally provided as an integral part of the device thatit powers. A power supply cord is typically provided to connect thepower supply in to an alternating current (AC) supply. The AC supply isusually obtained from a public power grid.

[0003] Within the power supply, a transformer is usually provided toreduce a voltage of the AC supply to a level convenient for use within aset of integrated circuits of the audio device. The reduced voltage isoften rectified within the power supply to further simplify powering theintegrated circuits.

[0004] As a recent trend, unitary power supplies have become availablethat are separate from the devices which they power. Often the newlyavailable power supplies are provided with their own enclosure and acord for connecting the power supply to the device that it is intendedto power. A set of prongs are usually provided on an exterior surface ofthe enclosure for engaging a wall outlet or power strip.

[0005] While the unitary power supplies are useful, they are ofteninconvenient to use. Because of the size of the enclosure, only one (orat most two) power supplies may be used in adjacent outlets. Because ofthe importance of audio devices, a need exists for a more convenient wayof powering audio devices.

SUMMARY OF THE INVENTION

[0006] A method and apparatus are described for providing power to anaudio signal processor. The method includes the steps of providing areceptacle for a housing of a voltage converting power supply within anenclosure of the audio signal processor and removably disposing thevoltage converting power supply within the enclosure of the audio signalprocessor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007]FIG. 1 is a perspective view of an audio system in accordance withan illustrated embodiment of the invention;

[0008]FIG. 2 is a rear prespective view of the base station of thesystem of FIG. 1;

[0009]FIG. 3 is a cross-sectional view of the power supply of the basestation of FIG. 2;

[0010]FIG. 4 is a top cut-away view of the base station of FIG. 2;

[0011]FIG. 5 is a block diagram of the signal processing functionsperformed by the base station of FIG. 2;

[0012]FIG. 6 is a detailed schematic of the block diagram of FIG. 5;

[0013]FIG. 7 is a detailed schematic of the block diagram of FIG. 5;

[0014]FIG. 8 is a top view of a circuit board used within the basestation of FIG. 2 and

[0015]FIG. 8 is a bottom view of a circuit board used within the basestation of FIG. 2.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0016]FIG. 1 depicts a microphone/amplifier system 10 under anillustrated embodiment of the invention. The system 10 may be used inany of a number of environments where the microphone user cannot beencumbered by a wires connected to an amplifier.

[0017] The system 10 includes a handheld microphone transmitter 12,belt-worn transmitter 16 and base station receiver 14. As would befamiliar to persons of skill in the performing arts, the transmitters12, 16 are equipped with a radio-frequency (RF) transmitter. The RFtransmitter may be of a relatively low power and have a relatively shortrange. During use, the transmitters 12, 16 may transmit a signal 13, 22to the base station receiver 14.

[0018] The transmitter 16 may be provided with a clip 18 that may beattached to a belt of the user (not shown). An antenna 20 may beprovided for transmitting a signal 22 to an antenna 24 of the basestation 14.

[0019] The base station 14 and transmitters 12, 16 may include a channelselector 26. The channel selector 26 may be used to select one of anumber of RF channels, free of noise from nearby noise sources.

[0020] A squelch control 41 (FIG. 2) may be provided on a back surfaceof an enclosure 15 of the base station 14. The squelch control 41 may beused to further reduce interference from the other noise sources.

[0021] The base station 14 may also include a volume control 28. Thevolume control 28 may be used to control an amplitude of an outputsignal available through an AF output 43.

[0022] The base station 14 may receive and amplify the signal receivedfrom the transmitters 12, 16. The amplified signal may, in turn, beprovided to a power amplifier and speakers (not shown) through the AFout 43.

[0023] In order to reduce space, the base station 14 may be equippedwith a removable, unitary power supply 30. The enclosure 15 of the basestation 14 may be provided with a receptacle 32 (FIG. 2) to slidablyreceive the unitary power supply 30. A set of dimensions of the insideof the receptacle 32 may be complementary to (e.g., ⅛ inch larger than)the outer dimensions of the power supply 30.

[0024] To prevent insertion of the power supply upside down, the sides60 (FIG. 3) of the power supply 30 and the sides of the receptacle 32may be tapered. More specifically, the edge 60 may taper inwards by anappropriate angle (e.g., 5 degrees) to ensure proper insertion of thepower supply 30 into the enclosure 15 of the power supply 30.

[0025] As shown in FIG. 2, the power supply 30 may be easily andconveniently moved 34 into and out of the receptacle 32. Once fullyinserted into the receptacle 32, the power supply 30 may besubstantially enclosed by the enclosure 15 with only a back surface ofthe power supply 30 exposed for making power connections.

[0026] Once the power supply 30 is fully inserted into the receptacle32, a resiliently biased detent (e.g., a peg) 42 may engage a recessedarea 46 of the power supply 30 securing the power supply within thereceptacle 32. Alternatively, the detent 42 may engage a back edge of anenclosure of the power supply 30, thereby securing the power supplywithin the receptacle 32.

[0027] Whether inserted into the receptacle 32, or not, an external setof conductors 36 may be provided to couple electrical power from thepower supply 30 to the base station 14. A plug 38 may be provided on oneend of the conductors 36 to engage an electrical receptacle 40 on theenclosure 15. The receptacle 40 may receive power from the plug 38 and,in turn, function as a source of power for the base station 14.

[0028] Also provided on the power supply 30 is a recessed male plug 50.The recessed plug 50 may be adapted to receive a female plug 52 of anexternal power cord (mains plug) 54. The power supply cord 54 may beprovided to conduct AC power from another male plug 56 to the femaleplug 52. The male plug 56 may receive power from a wall outlet or outletstrip, in turn, receiving power from a public utility.

[0029] In order to further reduce interference, the power supply 30 andreceptacle 32 may be located remotely from any low-level signalprocessing functions. FIG. 4 may be used to depict to top view of acomponent layout map of the base station 14. As shown, the power supply30 may be substantially located at a first end of the base station 14.In contrast, low-level signal processing of a circuit board 66 may belocated proximate a second end of the base station 14.

[0030] The positioning of the power supply 30 at an opposing end of thebase station 14 allows the low-level signal processing board 66 to beshielded from interference. For example, a separate shield 68 may beinstalled around the receptacle 32 to further shield a class 2transformer 64 and rectifier 62 of the power supply 30.

[0031] In addition, a person of skill in the art would recognize theimportance of the specifics of the physical separation between thetransformer 64 and noise sensitive signal processing elements. Forexample, FIG. 5 is a block diagram of signal processing functionsoccurring within the base station 14 and FIGS. 6 and 7 are detailedschematics of the physical devices providing the processing functions ofthe circuit of the base station 14. FIGS. 8 and 9 are top and bottomviews of the layout of the circuit board of the base station 14 showingthe physical separations of the noise sensitive signal processingelements and the transformer 64.

[0032] The bandpass filtering provided by FIL 30 and the second mixingfunctions occurring within IC 100 (FIGS. 5-7) would be recognized asbeing functions that would be particularly susceptible to noise. Inorder to reduce noise, a separation of 5 cm may be provided between thefilter FIL 30 and the transformer 64. A separation of 7.5 cm may existbetween the IC100 and the transformer 64.

[0033] Another sensitive element may be the tank circuit used inconjunction with the second mixer of the IC100. An inductor L100 of thistank circuit may be placed 7.5 cm from the transformer 64.

[0034] Further, the AF OUT provided through connector JK201 would berecognized as another sensitive device. The separation between theconnector JK201 and transformer 64 may be 6 cm.

[0035] In order to improve the separation between the noise sensitivecomponents and the transformer 64, other components may be moved closerto the transformer 64 to allow greater separation for the noisesensitive components. In effect, the separation of the sensitivecomponents may be achieved by preferentially separating noise sensitivecomponents at the expense of less sensitive components.

[0036] Under the illustrated embodiment, the base station 14 may be usedwith an integral power supply 30 (i.e., the power supply 30 insertedinto the receptacle 32) or with the power supply 30 located remotelyfrom the base station 14. The ability of the base station 14 to use thepower supply 30 in either configuration improves the utility of the basestation 14 in a number of regards. First, the use of a removable powersupply 30 eliminates obstructions at the power source by providing atransformer module that may be located away from the power source withinthe enclosure 15. For example, a common complaint of prior art walladapter units is that they take up too much room in an audio equipmentpower rack or power strip.

[0037] Further, the integrated AC supply 30 can located at anyconvenient location. This is of benefit when many base stations 14 areto be used in close proximity to avoid interference among receivers 14.

[0038] Further the external power cord 54 may be equipped with anIEC-approved AC mains plug 56. This allows the end user to use whicheverAC plug configuration is appropriate for his/her country.

[0039] Because the IEC mains cord 54 allows cables to be exchanged, itis easy for the end user to alter the length of the AC cable 54. Notonly does this make things neater and more convenient, but it also helpsin reducing hum and interference.

[0040] A specific embodiment of a method and apparatus for providingpower to an audio device has been described for the purpose ofillustrating the manner in which the invention is made and used. Itshould be understood that the implementation of other variations andmodifications of the invention and its various aspects will be apparentto one skilled in the art, and that the invention is not limited by thespecific embodiments described. Therefore, it is contemplated to coverthe present invention and any and all modifications, variations, orequivalents that fall within the true spirit and scope of the basicunderlying principles disclosed and claimed herein.

1. A method of providing power to an audio signal processor, such methodcomprising the steps of: providing a receptacle for a housing of avoltage converting power supply within an enclosure of the audio signalprocessor; and removably disposing the voltage converting power supplywithin the enclosure of the audio signal processor.
 2. The method ofproviding power to an audio signal processor as in claim 1 furthercomprising disposing a receptacle for a plug of an external power sourcewithin the housing of the power supply.
 3. The method of providing powerto an audio signal processor as in claim 1 further comprising providinga set of external conductors for coupling the power supply to the audiosignal processor.
 4. The method of providing power to an audio signalprocessor as in claim 3 further comprising disposing an electricalreceptacle in the enclosure of the audio signal processor for couplingpower from the power supply to the audio signal processor.
 5. The methodof providing power to an audio signal processor as in claim 3 furthercomprising disposing a plug on an end of the external conductors forengaging the electrical receptacle in the enclosure of the audio signalprocessor.
 6. The method of providing power to an audio signal processoras in claim 3 further comprising defining the audio signal processor asbeing an audio amplifier.
 7. The method of providing power to an audiosignal processor as in claim 1 further comprising providing a inner setof dimensions of the receptacle that are complementary to an outer setof dimensions of the converting power supply.
 8. The method of providingpower to an audio signal processor as in claim 7 further comprisingtapering the power supply and receptacle to prevent improper insertion.9. The method of providing power to an audio signal processor as inclaim 7 further comprising preferentially separating noise sensitivesignal processing components from a transformer of the voltageconverting power supply.
 10. The method of providing power to an audiosignal processor as in claim 9 further comprising shielding the noisesensitive signal processing components from the transformer.
 11. Anapparatus for providing power to an audio signal processor, suchapparatus comprising: a voltage converting power supply; and areceptacle disposed within an enclosure of the audio signal processor,said receptacle being adapted to removably receive the voltageconverting power supply.
 12. The apparatus for providing power to anaudio signal processor as in claim 11 further comprising a receptaclefor a plug of an external power source disposed within the housing ofthe power supply.
 13. The apparatus for providing power to an audiosignal processor as in claim 11 further comprising a set of externalconductors adapted to couple the power supply to the audio signalprocessor.
 14. The apparatus for providing power to an audio signalprocessor as in claim 13 further comprising an electrical receptacledisposed in the enclosure of the audio signal processor for couplingpower from the power supply to the audio signal processor.
 15. Theapparatus for providing power to an audio signal processor as in claim13 further comprising a plug disposed on an end of the externalconductors for engaging the electrical receptacle in the enclosure ofthe audio signal processor.
 16. The apparatus for providing power to anaudio signal processor as in claim 13 wherein the audio signal processorfurther comprises an audio amplifier.
 17. The apparatus for providingpower to an audio signal processor as in claim 11 wherein an innersurface of the receptacle and an outer surface of the voltage convertingpower supply further comprise a complementary set of dimensions.
 18. Themethod of providing power to an audio signal processor as in claim 17wherein the receptacle and converting power supply further comprise atapered cross-section.
 19. An apparatus for providing power to an audiosignal processor, such apparatus comprising: a voltage converting powersupply; and means disposed within an enclosure of the audio signalprocessor for removably receiving the voltage converting power supply.20. The apparatus for providing power to an audio signal processor as inclaim 19 further comprising means disposed within the housing of thevoltage converting power supply for receiving power from an externalsource.
 21. The apparatus for providing power to an audio signalprocessor as in claim 19 further comprising means coupled to the meansfor receiving power for coupling the power supply to the external powersource.
 22. The apparatus for providing power to an audio signalprocessor as in claim 19 further comprising means disposed in theenclosure of the audio signal processor for coupling power from thepower supply to the audio signal processor.